Using MobiLinc Pro (v2.0.7) on an Android phone (v 6.0.1), should I be able to connect using HTTPS to my old ISY 99i/iR (running v.3.3.10 firmware and v4.4.6 UI)? I can't seem to make it work. It does work just fine on a local (Wifi) network, and I'm comfortable that the port fowarding is set up correctly for external access (it works for other devices on the network). Thanks!

Google, back in OS 5, removed old HTTPS ciphers due to security concerns. The old ISY-99i (firmware 3.3.10) only supported these old (insecure) HTTPS ciphers. As a result Android 5+ and iOS 9+ devices no longer can connect to firmware 3.3.10 over HTTPS.

You can still use HTTP but the recommended solution, if you think you'll be keeping the ISY/INSTEON or want to add Z-Wave to the mix, is to upgrade to the ISY-994i. If you contact UDI Sales and ask about their upgrade options for ISY-99i users, they can give you the upgrade details. Please contact sales@universal-devices.com